Interest in wireless communication, particularly personal wireless communication, increased more and more during the last few decades, and user demand for the ability to transmit and receive information wirelessly has proven insatiable. Driven by high and growing demand, developers and manufacturers are constantly seeking ways to increase the information that can be transmitted and received by network infrastructure and user equipment. Finding such ways poses increasing challenges, as the desire to communicate large volumes of information combines with a strong and growing desire to use smaller and lighter equipment. New techniques, such as the use of submicron CMOS process to implement radio receivers, frequently encounter problems such as the need to operate using lower supply voltages, new sources of noise, such as 1/f noise, and stricter requirements from radio standards such as LTE 20 MHz carrier aggregation that employ closely spaced frequencies and employ subcarriers to carry information such as operational information.
Receivers operating under such conditions are bound by numerous requirements. They need to accurately receive wanted signals that may comprise subcarrier information and they need to reject unwanted signals. Such requirements present a need for equalization, the adjustment of signal strength of varying frequencies. An equalizer needs to admit wanted frequencies and attenuate undesired frequencies, and needs to present characteristics required by the application in which it is used.